CRS1991

My 2009 RX 350's condencer fan will not kick on i checked all the wiring on the fans themselves and when i throw ground to the white wire the fans will kick on the RX also will not pump out cold air. I Believe both of these problems are combined. This vehicle was wrecked at one point in time and all the A/C stuff was replaced. All help is appreciated.

cartman57

Might be low on freon, low pressure switch won't allow the fans or compressor to turn on.
Have you had it checked?

CRS1991

The A/C is charge to manufacture's recomendations. Which is 1.04-1.17 pounds.

cartman57

Does the compressor turn on? You'll hear an audible 'click' in the engine area and engine might adjust idle automatically.
Difficult to diagnose on the forum, lots of variables involved.
Checked all fuses with a meter?

CRS1991

Yes the compressor clutch ingages and it does turn on and all fuses are fine with 12.4 volts going to them. Is there a ground location i can check to verify that the ground is making conection? Could the relay be causing the issus with the fans not going on? It is also about 105 degrees today so the fans should pretty well kick on when the vehicle starts.

cartman57

When you grounded it in your original post did cold air come out of the vents?
Very difficult to know where a problem is, you stated it was in a wreck and the a/c stuff was replaced, did it ever function properly before or after replacement of parts?

Could be faulty relay not getting internal ground contacts.
Don't know where a common ground could be located, no wiring diagrams available.

Good luck.

HtownBlue

Check the CONNECTOR from the Fan to the FAN ECU. This is a far more common problem than people realize. Closely play with the connector itself to ensure that connection is being made WITHIN THE PLASTIC CONNECTOR ITSELF. I had this same issue. The A/C would only cool while car was moving (air flow over condensor), but would not cool when at idle.

CRS1991

Well a new up date fans will kick on when the car gets up to temp just not when the a/c is turned on. Could it need reprogrammed at the dealer or could it be a broken wire?

cartman57

Fan(s) should come on when the a/c is on no matter what the engin temp is.
There are safety's built into the system that'll not allow it to turn on if one were to fail.
Should also come on when the defrost is set.
Could be a broken wire somewhere, how familiar are you with a DVM?

CRS1991

The fans do not come on when the defrost is on. There is ground to the fan ECU. I have been using a Power probe to verify I have 12 volts to the fans and to make sure things are grounded also to ground out the fans to turn them on.

HtownBlue

Again, CHECK THE PLASTIC CONNECTOR that plugs INTO the ECU FROM THE FAN. Also, when on DEFROST the fan will not come on because you are not using the A/C. If the A/C clutch is engaged, the fans should be working and running. If they are not, the problem is within the ECU (highly highly unlikely) or it is within the connector to the ecu unit located on fan housing.

Please check the wire connection to the metal prong INSIDE THE PLASTIC CONNECTOR. You are having the exact issue I was.

CRS1991

I have checked the plug in a few times. They are making contact. The fan will kick on when the vehicle is up to temp so they have to be plugged in. I am thinking that I have a deeper problem then I was originally thinking. Possibly the ecu has taken a crap or its even deeper.

thomas1

Usually the AC connection is paralled to the fan to provide either a ground or hot....Maybe that wire is messed up.

HtownBlue

The radiator fan connection is not the one that is often the issue. Unless you took apart the condenser fan connector, applied pressure with a pair of pliers or electrical connection tool, I would not rule it out. I thought my ECU was blown until I spent 350 dollars to replace it and discovered it made no difference. Then I took apart the connectors and made sure they were making solid contact within the connector to the prong. That solved the issue.

I do have a perfectly good newly purchased FAN ECU I would gladly sell you for cheaper than you can get it in the shop. It is still in the Toyota box.